Indoor unit

ABSTRACT

An indoor unit, being configured to constitute a refrigeration apparatus including a refrigerant circuit, includes: a heat exchanger; and a plurality of refrigerant pipes. R32 refrigerant is enclosed in the refrigerant circuit. At least one of the plurality of refrigerant pipes that circulates the R32 refrigerant has an outer diameter of (Do-1)/8 inches while another of the plurality of refrigerant pipes that circulates R410A refrigerant has an outer diameter of Do/8.

TECHNICAL FIELD

The present invention relates to an indoor unit.

BACKGROUND

A refrigerant circuit included in a refrigeration apparatus such as anair conditioner is configured by an indoor unit and an outdoor unitconnected to each other. Many of the refrigerant circuits ofrefrigeration apparatuses currently available in the market use R410Arefrigerant. Meanwhile, from the viewpoint of suppressing globalwarming, R32 refrigerant having a smaller global warming potential (GWP)than that of R410A refrigerant has also been used in refrigerationapparatuses recently.

Patent Literature 1 (JP 5536817 B2) discloses an air conditioner usingR32 refrigerant. In this air conditioner, an outer diameter of aconnection pipe that connects an indoor unit and an outdoor unit is setto be smaller than that in a case where R410A refrigerant is enclosed ina refrigerant circuit. The purpose of this configuration is to reducethe amount of refrigerant enclosed in the refrigerant circuit or toreduce the amount of piping materials used.

PATENT LITERATURE

-   [Patent Literature 1] JP 5536817 B2

In recent years, however, refrigeration apparatuses such as airconditioners have been required not only to reduce the amount ofenclosed refrigerant and the amount of materials used, but also to beinstalled in a smaller space through downsizing of the apparatuses.Indoor units are also required to have a similar configuration.

An indoor unit usually includes parts such as a heat exchanger and, ifnecessary, an expansion valve. The indoor unit also includes arefrigerant pipe connected to these parts. As long as the refrigerantpipe has substantially the same outer diameter as the conventional pipe,the downsizing of the indoor unit is limited.

SUMMARY

Embodiments of the present invention downsize an indoor unit including arefrigerant pipe.

An indoor unit according to one or more embodiments of the presentinvention includes a heat exchanger and a plurality of refrigerantpipes. The indoor unit can constitute a refrigeration apparatusincluding a refrigerant circuit. R32 refrigerant is enclosed in therefrigerant circuit. At least one of the plurality of refrigerant pipeshas an outer diameter of (Do-1)/8 inches. Here, “Do/8 inches” representsan outer diameter of one of the refrigerant pipes in a case where R410Arefrigerant is enclosed in the refrigerant circuit.

With this configuration, the R32 refrigerant is used, and the outerdiameter of at least one refrigerant pipe is smaller than when R410Arefrigerant is used. Therefore, the indoor unit can be downsized and theinstallation space therefor can be reduced.

An indoor unit according to one or more embodiments of the presentinvention includes a heat exchanger and a plurality of refrigerantpipes. The indoor unit can constitute a refrigeration apparatusincluding a refrigerant circuit. R32 refrigerant is enclosed in therefrigerant circuit. At least one of the plurality of refrigerant pipeshas an outer diameter of 2/8 inches or less. The refrigeration apparatushas a rated capacity of 7.1 kW or more.

With this configuration, the R32 refrigerant is used, and the outerdiameter of at least one refrigerant pipe is 2/8 inches or less. In acase where R410A refrigerant is used, it is often difficult to reducethe outer diameter of the refrigerant pipe to such a level. Therefore,the indoor unit can be downsized and the installation space therefor canbe reduced.

An indoor unit according to one or more embodiments of the presentinvention is the indoor unit according to the first or second aspect,wherein the plurality of refrigerant pipes includes a liquid refrigerantpipe and a gas refrigerant pipe. The outer diameter of the refrigerantpipe mentioned in the first or second aspect is an outer diameter of theliquid refrigerant pipe.

With this configuration, the outer diameter of at least the liquidrefrigerant pipe is small. Therefore, the size reduction of the liquidrefrigerant pipe allows the indoor unit to be downsized.

An indoor unit according to one or more embodiments of the presentinvention is the indoor unit according to the third aspect, wherein theheat exchanger includes a refrigerant flow divider. The liquidrefrigerant pipe is connected to the refrigerant flow divider.

With this configuration, the liquid refrigerant pipe is connected to therefrigerant flow divider of the heat exchanger. It is therefore possibleto downsize the indoor unit by reducing the outer diameter of the liquidrefrigerant pipe that is disposed to be connected to the refrigerantflow divider.

An indoor unit according to one or more embodiments of the presentinvention is the indoor unit according to any one of the first to fourthaspects, wherein the rated capacity of the refrigeration apparatus is ina range of 7.1 kW to 16.0 kW inclusive.

With this configuration, the rated capacity of the refrigerationapparatus including the indoor unit is in the range of 7.1 kW to 16.0 kWinclusive. This makes it possible to reduce the installation space for arefrigeration apparatus that has relatively large rated power and iseasily enlarged. The “rated capacity” herein may alternatively bedescribed as the “nominal capacity” in a product catalog or aninstruction manual of a refrigeration apparatus.

A refrigeration apparatus according to one or more embodiments of thepresent invention includes a refrigerant circuit that implements arefrigeration cycle by flow of refrigerant. The refrigeration apparatusincludes an indoor unit, an outdoor unit, and a connection pipe. Theindoor unit is the one according to any one of the first to fifthaspects. The connection pipe connects the indoor unit and the outdoorunit.

With this configuration, at least one refrigerant pipe in the indoorunit of the refrigeration apparatus has a small outer diameter.Therefore, the refrigeration apparatus can be downsized and theinstallation space therefor can be reduced.

The indoor units according to one or more embodiments of the presentinvention are downsized, so that the installation space therefor can bereduced.

The refrigeration apparatus according to one or more embodiments of thepresent invention is downsized, so that the installation space thereforcan be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a refrigeration apparatus 1 includingan indoor unit 3 according to one or more embodiments of the presentinvention.

FIG. 2 is a plan view of an internal configuration of the indoor unit 3according to one or more embodiments.

FIG. 3 is a side view of the internal configuration of the indoor unit 3according to one or more embodiments.

FIG. 4 is a plan view of a liquid refrigerant pipe 31 of the indoor unit3 according to one or more embodiments.

FIG. 5 is a side view of the liquid refrigerant pipe 31 of the indoorunit 3 according to one or more embodiments.

FIG. 6 is a schematic diagram of a refrigeration apparatus 1 includingan indoor unit 3 according to one or more embodiments.

FIG. 7 is a schematic diagram of a refrigeration apparatus 1 includingan indoor unit 3 according to one or more embodiments.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention and modificationsthereof will be described with reference to the drawings. Note that aspecific configuration of the indoor unit according to the presentinvention is not limited to those in the following embodiments andmodifications, but can be changed without departing from the spirit ofthe invention.

(1) Overall configuration of refrigeration apparatus 1

FIG. 1 illustrates a refrigeration apparatus 1 including an indoor unit3 according to one or more embodiments of the present invention. Therefrigeration apparatus 1 is configured as an air conditioner, and cancool or heat the interior of a room in, for example, a building througha vapor compression refrigeration cycle. The refrigeration apparatus 1includes an outdoor unit 2, an indoor unit 3, and a liquid-refrigerantconnection pipe 4 and a gas-refrigerant connection pipe 5 that connectthe outdoor unit 2 and the indoor unit 3. The outdoor unit 2, the indoorunit 3, the liquid-refrigerant connection pipe 4, and thegas-refrigerant connection pipe 5 constitute a vapor compressionrefrigerant circuit 6. R32 refrigerant is enclosed in the refrigerantcircuit 6.

A rated capacity of the refrigeration apparatus 1 is in the range of 7.1kW to 16.0 kW inclusive. The “rated capacity” herein means a valueequivalent to the “nominal capacity” described in a product catalog oran instruction manual of the outdoor unit 2.

(2) Configuration of each part of refrigeration apparatus 1

(2-1) Outdoor unit 2

The outdoor unit 2 is installed outdoors. The outdoor unit 2 includes alow pressure receiver 7, a compressor 8, a four-way switching valve 9,an outdoor heat exchanger 10, an expansion valve 11, a liquid-sideshutoff valve 12, a gas-side shutoff valve 13, and an outdoor fan 14.The compressor 8 includes a compressor body 8a and an attached receiver8b. The outdoor unit 2 further includes refrigerant pipes 15 to 21 thatconnect the parts. The configuration of the outdoor unit 2 describedhere is merely an example, and it is possible to use otherconfigurations and parts alternatively.

(2-2) Indoor unit 3

The indoor unit 3 is installed indoors. The indoor unit 3 includes anindoor heat exchanger 22, an indoor fan 24, a liquid refrigerant pipe31, and a gas refrigerant pipe 32. The indoor heat exchanger 22 includesa refrigerant flow divider 25. The liquid refrigerant pipe 31 connectsthe refrigerant flow divider 25 of the indoor heat exchanger 22 to theliquid-refrigerant connection pipe 4. Here, the liquid refrigerant pipe31 may be either separate from or integral with the liquid-refrigerantconnection pipe 4. The gas refrigerant pipe 32 connects the indoor heatexchanger 22 and the gas-refrigerant connection pipe 5. Here, the gasrefrigerant pipe 32 may be either separate from or integral with thegas-refrigerant connection pipe 5.

(2-3) Liquid-refrigerant connection pipe 4 and gas-refrigerantconnection pipe 5 The liquid-refrigerant connection pipe 4 and thegas-refrigerant connection pipe 5 are constructed on site when therefrigeration apparatus 1 configured as an air conditioner is installedin an installation place in, for example, a building. One end of theliquid-refrigerant connection pipe 4 is connected to the liquid-sideshutoff valve 12 of the outdoor unit 2. The other end of theliquid-refrigerant connection pipe 4 is connected to a liquid-side endof the indoor heat exchanger 22 of the indoor unit 3 directly, orindirectly through the liquid refrigerant pipe 31 separate from theliquid-refrigerant connection pipe 4. One end of the gas-refrigerantconnection pipe 5 is connected to the gas-side shutoff valve 13 of theoutdoor unit 2. The other end of the gas-refrigerant connection pipe 5is connected to a gas-side end of the indoor heat exchanger 22 of theindoor unit 3 directly, or indirectly through the gas refrigerant pipe32 separate from the gas-refrigerant connection pipe 5.

(3) Operation of refrigeration apparatus 1

At the time of cooling, the refrigeration apparatus 1 performs arefrigeration cycle in which the refrigerant is circulated through theoutdoor unit 2, the liquid-refrigerant connection pipe 4, the indoorunit 3, and the gas-refrigerant connection pipe 5 in that order. At thistime, the indoor heat exchanger 22 functions as a heat absorber thatremoves heat from indoor air.

At the time of heating, the refrigeration apparatus 1 performs arefrigeration cycle in which the refrigerant is circulated through theoutdoor unit 2, the gas-refrigerant connection pipe 5, the indoor unit3, and the liquid-refrigerant connection pipe 4 in that order. At thistime, the indoor heat exchanger 22 functions as a heat radiator thatreleases heat into the indoor air.

(4) Detailed configuration of indoor unit 3

Generally, the indoor unit 3 is required to be installed in a smallerspace. The size of the indoor unit 3 tends to be larger as therefrigeration apparatus 1 has a larger rated capacity. In order toreduce the installation space for the indoor unit 3, it is necessary todownsize the refrigerant pipes such as the liquid refrigerant pipe 31and the gas refrigerant pipe 32 as well as downsizing the parts such asthe indoor heat exchanger 22.

In this case, therefore, R32 refrigerant is enclosed in the refrigerantcircuit 6, and an outer diameter of the liquid refrigerant pipe 31,among the refrigerant pipes 31 and 32, is smaller than that in anoutdoor unit used in a refrigeration apparatus having the same ratedcapacity and in which R410A refrigerant is enclosed in the refrigerantcircuit 6. As described above, the rated capacity of the refrigerationapparatus 1 according to one or more embodiments is in the range of 7.1kW to 16.0 kW inclusive. In an indoor unit of a conventionalrefrigeration apparatus having this level of rated capacity and usingR410A refrigerant, an outer diameter of a liquid refrigerant pipe is,for example, 3/8 inches, and an outer diameter of a gas refrigerant pipeis, for example, 5/8 inches. This is generically referred to herein as“in the indoor unit for R410A, the outer diameter of the refrigerantpipe is Do/8 inches”.

On the other hand, an outer diameter of at least one of the refrigerantpipes installed inside the indoor unit 3 of the refrigeration apparatus1 is set to (Do-1)/8 inches, which is one size smaller than that in theindoor unit for R410A. For example, the liquid refrigerant pipe 31 ofthe indoor unit 3 is manufactured to have an outer diameter of 2/8inches or less. With this configuration, herein, the liquid refrigerantpipe 31 having a reduced pipe diameter can reduce the installation spacefor the indoor unit 3.

FIGS. 2 and 3 illustrate an internal configuration of the indoor unit 3.The liquid refrigerant pipe 31 is connected to the refrigerant flowdivider 25 of the heat exchanger 22. The gas refrigerant pipe 32 isconnected to an end of the heat exchanger 22 without the refrigerantflow divider 25. As illustrated in FIGS. 4 and 5, the liquid refrigerantpipe 31 has a bent portion B1 and a bent portion B2, which are bent. Theshape of the liquid refrigerant pipe 31 is not limited to this. Forexample, the liquid refrigerant pipe 31 may have only one bent portion.Alternatively, the liquid refrigerant pipe 31 may have three or morebent portions.

In a case of reducing the outer diameter of the refrigerant pipe havingat least one bent portion, a bending radius of the bent portion can bereduced as compared with before reducing the outer diameter of therefrigerant pipe. Such a reduction in the bending radius can lead to afurther reduction in the space occupied by the refrigerant pipe.Therefore, the bending radius is expected to be reduced also at the bentportion B1 and the bent portion B2 in the liquid refrigerant pipe 31 ofone or more embodiments. This can lead to a significant reduction in theinstallation space for the indoor unit 3.

(5) Characteristics

(5-1)

The R32 refrigerant is used, and the outer diameter of at least theliquid refrigerant pipe 31 is 2/8 inches or less, which is smaller thanwhen R410A refrigerant is used. Therefore, the indoor unit 3 can bedownsized and the installation space therefor can be reduced.

(5-2)

The liquid refrigerant pipe 31 is connected to the refrigerant flowdivider 25 of the heat exchanger 22. It is therefore possible todownsize the indoor unit 3 by reducing the outer diameter of the liquidrefrigerant pipe 31 that is designed to be connected to the refrigerantflow divider 25.

(5-3)

The rated capacity of the refrigeration apparatus 1 including the indoorunit 3 is in the range of 7.1 kW to 16.0 kW inclusive. Therefore, therefrigeration apparatus 1 having a rated capacity in this range can beinstalled in a smaller space.

(5-4)

Since the refrigeration apparatus 1 includes such an indoor unit 3, theinstallation space for the entire refrigeration apparatus 1 can bereduced.

In one or more embodiments, the refrigerant circuit 6 in the indoor unit3 does not include an expansion valve. Alternatively, as illustrated inFIG. 6, an indoor unit 3 may include an indoor expansion valve 23. Theindoor expansion valve 23 is provided on a liquid refrigerant pipe 31.Therefore, the liquid refrigerant pipe 31 is divided into a first liquidpipe 33 and a second liquid pipe 34 by the indoor expansion valve 23.The first liquid pipe 33 is connected to a heat exchanger 22 and theindoor expansion valve 23. The second liquid pipe 34 connects the indoorexpansion valve 23 and a liquid-refrigerant connection pipe 4. Thesecond liquid pipe 34 may be either separate from or integral with theliquid-refrigerant connection pipe 4.

An outer diameter of at least one of the refrigerant pipes 32, 33, and34 is (Do-1)/8 inches, which is one size smaller than Do/8 inches, i.e.,the outer diameter of one of the refrigerant pipes in the indoor unit ofthe refrigeration apparatus using R410 refrigerant. For example, theouter diameter of the first liquid pipe 33 is reduced from 3/8 inches to2/8 inches as in the above described embodiments. With thisconfiguration, the installation space for the indoor unit 3 includingthe indoor expansion valve 23 can be reduced.

In one or more embodiments, the refrigeration apparatus 1 is of aso-called pair type; in other words, one indoor unit 3 is connected toone outdoor unit 2. Alternatively, as illustrated in FIG. 7, arefrigeration apparatus 1 of a so-called multiple type may be configuredwith a plurality of indoor units 3 connected to one outdoor unit 2. Notethat the indoor fan 24 is not illustrated in the drawing. Alternatively,each indoor unit 3 may be a product including the indoor expansion valve23 according to the first modification. This makes it possible todownsize the multiple-type refrigeration apparatus 1.

In one or more embodiments, the refrigeration apparatus 1 is configuredas an air conditioner. Alternatively, the refrigeration apparatus 1 maybe configured as a freezer, a hot water supply apparatus, or any otherapparatus that uses a refrigeration cycle. As a result, a refrigerationapparatus other than an air conditioner can be downsized.

Although the disclosure has been described with respect to only alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that various other embodiments maybe devised without departing from the scope of the present invention.Accordingly, the scope of the invention should be limited only by theattached claims.

REFERENCE SIGNS LIST

-   1 Refrigeration apparatus-   2 Outdoor unit-   3 Indoor unit-   4 Liquid-refrigerant connection pipe-   5 Gas-refrigerant connection pipe-   6 Refrigerant circuit-   22 Indoor heat exchanger-   23 Indoor expansion valve-   31 to 34 Refrigerant pipe

1. An indoor unit being configured to constitute a refrigerationapparatus including a refrigerant circuit, the indoor unit comprising: aheat exchanger; and a plurality of refrigerant pipes, R32 refrigerant isenclosed in the refrigerant circuit, and at least one of the pluralityof refrigerant pipes that circulates the R32 refrigerant has an outerdiameter of (Do-1)/8 inches while another of the plurality ofrefrigerant pipes that circulates R410A refrigerant has an outerdiameter of Do/8.
 2. An indoor unit being configured to constitute arefrigeration apparatus including a refrigerant circuit, the indoor unitcomprising: a heat exchanger; and a plurality of refrigerant pipes,wherein R32 refrigerant is enclosed in the refrigerant circuit, at leastone of the plurality of refrigerant pipes has an outer diameter of 2/8inches or less, and the refrigeration apparatus has a rated capacity of7.1 kW or more.
 3. The indoor unit according to claim 1, wherein theplurality of refrigerant pipes includes: a liquid refrigerant pipe; anda gas refrigerant pipe, and refrigerant pipe circulates the R410Arefrigerant and has an outer diameter of Do/8 inches.
 4. The indoor unitaccording to claim 3, wherein the heat exchanger includes a refrigerantflow divider, and the liquid refrigerant pipe is connected to therefrigerant flow divider.
 5. The indoor unit according to claim 1,wherein the rated capacity of the refrigeration apparatus is greaterthan or equal to 7.1 kW and less than or equal to 16.0 kW.
 6. Arefrigeration apparatus including a refrigerant circuit that implementsa refrigeration cycle by flow of refrigerant, the refrigerationapparatus comprising: the indoor unit according to claim 1; an outdoorunit; and a connection pipe that connects the indoor unit and theoutdoor unit.
 7. A refrigeration apparatus including a refrigerantcircuit that implements a refrigeration cycle by flow of refrigerant,the refrigeration apparatus comprising: the indoor unit according toclaim 2; an outdoor unit; and a connection pipe that connects the indoorunit and the outdoor unit.